How to Perform an Exchange Migration

In this phase, existing mail accounts andscripts. All scripts for managing batch processes
messages are migrated from the existingmust be completed and tested prior to
messaging environment to the Microsoft------------------------Choosing Full or Limited Migration
Exchange 2003 environment. Your migration
strategy must be executed in a manner that isAccounts to migrate can be defined based on
transparent and that has the minimum possiblebusiness rules (for example, all mail accounts in
impact on your current e-mail users.To accomplishgood standing or priority accounts requiring early
these goals, an effective migration strategy andaccess to features not offered in the exiting mail
appropriate migration tools must be designed andsystem).If you are not going to migrate the entire
implemented. They must address all aspects ofpopulation at one time, there are certain
system migration, including networking, externalconsiderations you need to plan for. For limited
interfaces, account synchronization, managementmigration, you must configure the Microsoft
systems, and parallel operations.This chapterExchange 2003 system for POP proxy in order to
contains the following sections:Developing aretrieve mail from the legacy system for
Migration StrategyPreparing the Migration PlanUsingunmigrated accounts and mailboxes. The
Migration UtilitiesTips for a Successfularchitecture must also account for SMTP relay
MigrationRefer to the Microsoft Exchange 2003during Proxy mode in order to deliver appropriate
Migration Guide for complete information onmail to the legacy system as well as to Microsoft
migration.Developing a Migration StrategyExchange 2003.The method of migrating account
The typical site where Microsoft Exchange 2003data must be identified and tested. Before the
is installed has an existing mail system thatlimited account migration can occur, a back-out
provides messaging services to its users. Migrationplan, migration quality assurance, and certification
is the act of moving or copying the data for allof migration must be resolved and validated by
users from the legacy (existing) system to thetesting.In many instances, new subscribers to mail
Microsoft Exchange 2003 system. Migration isservice at the customer site are added to the
performed so that all customers can be servicedMicrosoft Exchange 2003 system before migrated
by the Microsoft Exchange 2003 system, notaccounts from the legacy system. The benefits
simply those new subscribers following theof handling new registrations in Microsoft
installation of Microsoft Exchange 2003.Migration isExchange 2003 are that you may be able
the most complex facet of any deploymentto:Offer differentiated service
project. Even though this document provides aimmediately.Introduce Microsoft Exchange 2003 at
framework to follow for migration, no twoa measured pace.Ensure that no more users are
migrations are exactly alike, due to theadded to an obsolete system.Resuming Service
differences in each site's legacy mail system andOnce migration is completed, accounts are
its integrated systems and procedures. Aautomatically switched from Proxy mode to
successful migration depends upon accuratelyactive status. Users regain access to their
identifying all unique aspects of the system thatmailboxes and all messages that were deferred
are to be duplicated in Microsoft Exchange andduring migration are delivered to their intended
then duplicating these conditions throughrecipients. In addition, you must move operations
development and testing prior to the actualentirely to the Microsoft Exchange 2003 system
physical migration.The principal issues of concern inand deactivate the legacy system.A burn-in period
any migration to a new mail service are datashould be identified, over which the Microsoft
integrity and transparent cutover to production.Exchange 2003 system must be closely
Data integrity guarantees that all mail accounts,monitored for error conditions.Using Migration
stored messages, and associated personalUtilities
information and preferences (for example,There are multiple methods for the combined
address books, passwords, and so forth) aremigration of accounts and mailboxes. One method
accurately retained in the new mail system.is to transfer all accounts in a single migration.
Transparent cutover to production means thatThen, mailboxes can be transferred in batches.
the transition is handled quickly, cleanly, and withAnother method is to transfer a batch of
no disruption to the end-user experience.In typicalaccounts, then transfer a batch of corresponding
migrations, the total amount of time required formailboxes, and so on.Utilities that support the
a successful transition is a function of systemchosen strategy must then be developed and
complexity. Both the total number of mailtested. These tests should include timing of the
accounts and the total number of storedexecution of these utilities.This phase involves the
messages are significant factors. In addition,building of the migration utilities themselves and
migration time can be affected by system andmust include the design, development, and testing
site-specific issues.Any migration strategy mustof the migration utilities that are to be used to
address:Migrating accountsMigratingmigrate the mail from the existing system to the
mailboxesMigrating Accountsnewly implemented Microsoft Exchange 2003
This migration involves all of the information thatsystem. New tools have to be built very often
uniquely identifies and describes a user, includingbecause of the different source mail systems
class-of-service data that defines the service forthat can be in existence.Microsoft Exchange 2003
which users are subscribed. Account data must beoffers automated migration tools designed to
placed in the Microsoft Exchange 2003 systemstreamline the process of moving your service,
before message data. The first task is thereforeincluding built-in tools for services using Sendmail
to collect and transfer account data from theand Software.com's Post.Office. These flexible,
legacy system and then transfer it to themodular, and customizable tools are Perl scripts
Microsoft Exchange 2003 system.If your legacythat handle the export of directory, mailbox, and
system has domains and organizational units, youuser information from these other systems to
must prepare to migrate these also.Migratingfiles in Microsoft Exchange 2003-readable format
Mailboxes(based on LDIF), which are then imported into
This migration involves message data--the actualMicrosoft Exchange 2003. These tools enable you
messages to be migrated that belong to the user.to migrate all accounts at once or as incremental
The mailbox is simply a collection of theblocks of users. When migrating from a different
messages belonging to a particularmail system such as Netscape Messaging Server
account.Preparing the Migration Planor SIMS, Microsoft Exchange 2003's proxy
Migration involves significant planning, more sofeatures and robust export command set provide
than any other deployment task. This planning isa solid foundation for rapid development of
necessary because the activity is exposed tocustom export scripts.Tips for a Successful
existing users and will, in most cases, be the initialMigration
experience that users have of the new system.With the completion of the migration tests, the
It is very important to plan for every eventualityonly anticipated impact will be caused by the
in order to avoid problems during thedifference in functionality between mail systems.
migration.Refer to Appendix A for information onOnce the migration of accounts has started, the
how to obtain a sample migration plan.Migration istarget production environment becomes the
95 percent planning and 5 percent execution. Aproduction environment.The migration procedure
multitude of factors that must be considered ininvolves these discrete steps:Setting up Microsoft
order for a migration to succeed.The MigrationExchange 2003 in Proxy modeChanging the MX
Plan provides a detailed, step-by-step procedurerecordIdentifying accounts to be
for migrating accounts and mailboxes to MicrosoftmigratedExtracting account informationCreating
Exchange 2003. The deployment team shouldaccounts in Microsoft Exchange 2003Migrating
make several dry runs of this plan, with each drymessagesSetting Up Microsoft Exchange 2003 in
run resulting in a subsequent refinement of theProxy Mode
plan.Any migration plan should address theseMicrosoft Exchange must be configured for
considerations:Ensuring systemsProxy mode prior to activating the system. The
readinessCoordinating with other groups andproxy configuration permits the relay of message
identifying dependenciesVerifying softwareand service requests to the legacy system until
installation and configurationSetting up the testthe full migration has been achieved.In Proxy
systemProviding provisioning connectivityTestingmode, all incoming mail is directed to Microsoft
the migrationChoosing full or limitedExchange 2003. If the mail is for a user that does
migrationResuming serviceEnsuring Systemsnot have an Microsoft Exchange account, the mail
Readinessis relayed to the legacy system for delivery. If a
All systems to be tested must be ready anduser attempts to retrieve mail, but the user's
operational before testing begins. In additionmailbox is not yet located on the Microsoft
networks must be implemented as defined in theExchange 2003 system, the POP server will
architecture design (see Chapter 2).For eachconnect to the legacy system and will retrieve
original e-mail system, separate IP settings (eachthe mail from the legacy mailbox location.Changing
with unique "A" records in the DNS) must bethe MX Record
established for the following:Host Address This isIn order for mail to reach the Microsoft
the permanent IP assignment for the host.Exchange 2003 system (instead of the legacy
Service Address This is the address that is usedsystem), you must change the MX record in the
by all e-mail clients for a service. The ServiceDNS for the mail domain of the site, so that
Address will be re-assigned to Microsoft Exchangetraffic is directed to Microsoft Exchange
at the time of account migration.2003.With all of the mail directed to Microsoft
Service Proxy Address There must be a ServiceExchange, you can begin to burn-in the system
Proxy Address for each Service Address. The IPwith live loads and become accustomed to
number used for any Service Proxy Address willoperations administration even if there is no
match its respective Service Address. Theaccount data in the system. However, as soon as
Service Proxy Address will be used for proxythe system is activated, accounts are provisioned
targeting where proxy is used on the Microsoftdirectly into Microsoft Exchange
Exchange system. These can be de-assigned-------------------Note: This step can take a few
after all migrations are complete and when it ishours to be propagated over the
determined that a revert procedure is not-----------------------Identifying Accounts to Be
required.Coordinating with Other Groups andMigrated
Identifying DependenciesThe first step in migration is to determine which
Since any migration touches upon many aspectsexisting mail accounts will move to the Microsoft
of a company's operations, make sure youExchange 2003 system. Accounts to migrate can
coordinate the migration with all affected groupsbe defined based on business rules (for example,
and identify dependencies--that is, determining theall mail accounts in good standing, or priority
order in which systems should beaccounts requiring early access to features not
migrated.Verifying Software Installation andoffered in the existing mail system).Extracting
ConfigurationAccount Information
In addition to installing Microsoft Exchange 2003After defining the accounts to migrate, the next
(see Chapter 3) and verifying that all componentsstep is to extract account information from the
inter-operate, you must set correct Microsoftexisting mail system. Using the target account list,
Exchange environment settings for the root user.account information is exported into a file in LDAP
These include the correct $PATH,Data Interchange Format (LDIF). The standard
$LD_LIBARARY_PATH, and $Microsoft ExchangeLDIF format permits the importing of account
settings in order to access the Microsoftinformation from any existing mail system to an
Exchange migration tools.Setting Up the TestMicrosoft Exchange system. The scripts used
Systemhere can be customized to handle any
To validate a migration plan, the test systemsituation.Creating Accounts in Microsoft Exchange
should have the capacity of production systems,2003
including the proper storage volume configurationNext, accounts are created in the Microsoft
and failover configuration (service continuity). TheExchange directory based on the account
test system must have Internet connectivity, asinformation described in the LDIF file. As accounts
Proxy mode operations cannot be tested withoutare created, they are placed in Proxy mode,
this.Aside from equipment that mimics thecausing mail delivery to and access from
production system, test driver machines mustunmigrated accounts to be passed directly
also be available to power the migration andthrough to the old mail system, thus ensuring
capacity tests. The test drivers must becontinuous service to end users. During this phase,
configured with migration utilities as well as withif a user logs in and supplies an unknown
mail clients or other test utilities for accessing andusername, the Microsoft Exchange POP server
sending mail.At least one test host is required forconnects to the current e-mail system.Migrating
migration testing; this host acts as a surrogate forMessages
the actual online e-mail hosts and holds all mailboxThe last phase of migration involves moving mail
data required for testing.Providing Provisioningmessages from the existing mail system to the
ConnectivityMicrosoft Exchange system. Message migration
The provisioning interface must be validatedmay occur either as separate files or as a single,
before migration can occur. C API proceduresconcatenated file. However, some customization is
should be tested to ensure that modificationstypically required, since the way a message is
performed on the ISD are successful and arestored in the Message Store Server (MSS) can
propagated to the provisioning database. The Perldiffer from the standard mail format. This phase
API set for batch account migration also must berequires new accounts to run in Maintenance
tested. Last, administrative routines in themode, during which time these mailboxes are
provisioning system or ISD must be validated.Thisunavailable. For this reason, message migration is
testing is performed in a dual provisioningtypically performed in small increments during
environment. The purpose of dual provisioning isoff-peak hours.Exchange Migration plan for moving
to ensure the ability to revert to the legacy mailforward:Perform Due Diligence on your network
system in the event that the new mail system invia Remote Terminal Service ( Next Week)
not successful.For provisioning, automatic mailboxIdentify existing components - users, groups,
creation must be tested. Zero-length mailboxeslogin variables
are typically not migrated; rather, they are turnedDocument proposed AD structure
on in Microsoft Exchange 2003. The first time mailProject kickoff meeting (Friday)
is received or checked, the mailbox can beInstall Windows Server 2003 (Friday Night)
created. A large test database (representing theInstall Active Directory (Friday Night)
volume of anticipated accounts) must beConfigure, Patch and Connect (Friday Night)
test-migrated to ensure that the procedureReview Event Log, resolve any errors (Friday
works and that the destination ISD database canNight)
handle it.If possible, you should identify a group ofConnect AD environment to existing Windows
"friendly" users willing to assist in identifying any2000 (Friday Night)
problems or errorsTesting the MigrationIdentify existing printers (Saturday)
Before the migration can occur, comprehensiveIdentify existing components in Exchange
testing on the production system must be(Saturday)
completed. Migration test activities areBuild Exchange, configure, patch(Saturday)
"non-intrusive" to the existing mail system and areInstall and configure virus software,Spam solution
conducted from a separate system using actualand Fax Software(Saturday)
user account information and a test copy of theConfigure OWA in DMZ(Saturday)
production user data.The procedures forVerify Installation (Saturday)
extracting account data from the legacy systemPerform Mailbox Move (Saturday)
must be tested. The method and utilities to loadInstall Outlook 2003 on all desktops. (Saturday -
these accounts into the ISD must be validatedSunday)
through testing. Each class of service must beReview Event Log, resolve any errors (Sunday)
included, as well as each combination of accountSetup Test workstation/perform testing
attributes, such as forwarding, aliases, and(Sunday)
vacation replies.In addition, the process of movingOn-Site to handle any issues with the migration
mailboxes to the Microsoft Exchange 2003(Monday)The above steps are only an estimate
system must be tested. This process includes theof work needed to be perform a successful
method of suspending the account, the physicalmigration. After we perform the Due Diligence
transfer of messages and attachments, and theIntercore will have a more definite outline in MS
return of the account to active status.You shouldProject to fully detail the breadth of work needed
make any possible configuration changes toto perform the migration . This Due Diligence will
prevent network or system loading. In addition,identify issues that we can resolve before the
you must establish any special network, host, ormigration is performed.InterCore Technologies,
storage accommodations that may be requiredLLC opened it's doors in May of 1996. Our mission:
for testing. A special network configuration mayTo Provide a high level of computer consulting
be required to prevent traffic complicationsservices using the most experienced engineers at
introduced by migration testing. Another solutionfair prices. We believe in using a Business Value
may involve localization of the original mailboxapproach to every aspect of computer consulting.
storage to the Microsoft Exchange 2003This provides our clients with the most cost
-----------------------Note: Depending on theeffective solutions. We help our clients get more
particulars of a given migration, you may need towith their current technology investment.
create new scripts or modify existing migration